1. Field of the Invention
The present invention relates broadly to medical instruments. More specifically, this invention relates to instruments for inserting a punctum plug and a packaging for such instruments.
2. State of the Art
The surface of the eye and the inner surface of the eyelid are moisturized by tears constantly produced by glands around the eye. A tiny hole, known as the lacrimal punctum, at the inner corner of each upper and lower lid margin drains the tears away through ducts for proper circulation.
Patients, including contact lens wearers, who suffer from dry eye, or insufficient tear production, experience a great deal of discomfort because of insufficient lubrication between the lens and the surface of the eye. One solution is to occlude or block the lacrimal duct to prevent tear drainage. Permanent lacrimal occlusion can be performed surgically, typically by closing the punctal opening, whereas reversible occlusion can be performed by inserting a tiny plug into a portion of the lacrimal duct, such as the punctum. A typical punctum plug includes a cylindrical or frustoconical body, a larger head portion to retain the plug at the punctal opening, and a coaxial bore through the head portion and partially through the body at which the plug is coupled to the tip of an instrument during insertion.
A variety of instruments are available for inserting lacrimal occluders such as punctum plugs and canalicular implants. For example, Lacrimedics, Inc. of Rialto, Calif., has sold a canalicular implant preloaded on the tip of a wire stuck into a piece of foam. The wire is used to push the implant into the canaliculus. After the implant is deeply seated, the wire is withdrawn.
EagleVision, Inc. of Memphis, Tenn. sells the EP2 punctum plug inserter and dilator which is described in U.S. Pat. No. 5,741,292 to Mendius. This more complex device for punctal dilation and insertion includes a cylindrical body having a plug inserting tip at one end and an opposite punctum dilating end. An elongated button is arranged longitudinally along the body, and includes a slidable end and a fixed end positioned between the slidable end and the plug inserting tip. The button has an outwardly bowing inner surface spaced from the body such that when the button is pressed toward the body, the slidable end slides away from the plug inserting tip. A plug mounting wire is fixedly attached to the slidable end of the button, and slidably extends within the body and protrudes out of the plug inserting tip. A conventional punctum plug is attached to the protruding end of the wire. The mounting wire can be retracted by pressing on a button at a location between the proximal and distal ends of the mounting wire and thereby effect release of the plug.
In operation, one hand of the physician is placed against the face of a plug recipient, and the lid of the eye receiving the plug is pulled down to expose the punctal opening. The instrument is held in the other hand and the dilating tip is used to dilate the punctum. The instrument must then be turned around so that the plug inserting tip is now facing the eye, and the plug can then be inserted into the dilated punctum. It is noted that the device must be turned around carefully to prevent inadvertently dropping the instrument and to prevent unwanted contact with the plug (which may contaminate or dislodge the plug). Moreover, it must be turned around quickly, as the punctal opening begins to constrict within approximately five seconds after dilation. Once the plug is positioned in the punctum, the plug is released from the instrument by depressing the buttons, which retracts the wire and frees the plug.
FCI Ophthalmics of Marshfield Hills, Mass. sells a Ready-Set™ punctum plug system which also includes a plug inserter and punctal dilator instrument. The instrument is generally similar to the Mendius device, but includes a two-sided trigger with handles located on diametrically opposite sides of the body. When the handles are pressed toward a plug mounting pin and one another, the pin is retracted into the body, thereby dislodging the plug from the pin.
US Pub. No. 2004/0068286, also to Mendius, teaches a plug insertion instrument having a protective dilating cap covering the plug. The punctal opening can be dilated with the cap, and then the cap is removed to expose the plug at the same end as the dilator so that the plug can then be conveniently inserted into the punctum. The plug is deployed by pressing on a button attached to a proximal end of a plug mounting wire, with the plug mounted at the distal end of the wire. The button is pressed at a location between the proximal and distal ends of the wire to retract the wire and effect release of the plug.